DocuSign's CEO on getting in over your head (and succeeding)

Programmer by day, thrill-seeker by night: We talk to Keith Krach about what makes him tick.

FORTUNE — As the youngest-ever vice president and general manager of GMF Robotics, the industrial robotics division of automaker General Motors, Keith Krach used his early momentum in tech business to help found Rasna (which was sold in 1995 to Parametric Technologies for $500 million) and Ariba. He continued his entrepreneurial path by joining DocuSign — an electronic signature company that facilitates legal, contractual, and tax documents online — and becoming the company’s chairman and CEO.